Note: You must do this everytime you (re-)install or your kernel, because its (old) alsa-module overwrites the one you just installed.

Edit modprobe.conf

Add the following to /etc/modprobe.conf:

options snd-hda-intel model=medion

and reboot then.

Unmute channels

Open a terminal and type

alsamixer

Use the arrow keys to turn up volume where you need it.

How to mute your speakers and use your headset

You might have noticed that your speakers do not get muted automatically when you put in your earphones. Here's my solution to do that manually:
Open up alsamixer (like described before)
Mute Surround by pressing M (for mute), so it says MM instead of 00. Also turn down PCM to 65 or lower.

Now you won't hear anything from the built-in speakers, but you can use your earphones.

Graphicscard

There are two possible drivers you can use for the Nvidia 6150 Geforce Go. I recommend the non-free driver, because the open one had no mouse cursor as I tried it (which was really annoying). If you want 3d-allocation, you must use the closed source one.

Nv (free driver)

Installation:

pacman -Sy nv

Here's no customized xorg.conf yet. Go make one yourself following this guide and post it here.

Nvidia (non-free driver)

Installation:

pacman -Sy nvidia

Note: The xorg.conf is based on this one which was made for gentoo.[1]

Tweaks

Cpufrequtils

Cpufrequtils is a CPU Frequency Scaling, a technology used primarily by notebooks which enables the OS to scale the CPU speed up or down, depending on the current system load and/or power scheme. Note that the module you need to load at the CPU Frequency Driver part is powernow-k8.